@Syonyk zfs is weird for root? Don’t see that, been used for quite some time on BSDs just fine. In fact it has lots of benefits. Things like snapshots before upgrades/config changes/etc. So you can simply rollback easily to a known good working version. As long as you can boot the system to single-user or with a live image, you can roll it back. Easy, built-in quota support for home dirs and such. Easy to have a zvol per user as their home dir, no muss, no fuss. /var/log can be it’s own, size limited, so it doesn’t take over your entire root fs in the event of something over-logging, likewise with /tmp. So nice things like that.
For FreeBSD, it’s a painless process, and well supported. Initially you had to do some manual magic, but these days it’s just one other install option. I suppose it was too much to hope that Linux distros had moved on to allowing that as well. Ah well. 
@bombcar yeah, thanks for those, but it’s not that ephemeral. Already bought the license and have had it sitting around waiting for the laptop.
As for swap resize…it’s not the swap resize itself that’s the problem, it’s resizing a zfs pool. As this post says, trying to resize smaller is, in theory, maybe possibly capable. Not really though. It’s 𝘽𝙡𝙤𝙤𝙙𝙮 𝙅𝙤𝙝𝙣𝙨𝙤𝙣 𝙨𝙩𝙪𝙥𝙞𝙙. So can’t resize smaller, only larger.
In theory I can use a zvol for swap, but as pointed out by a ticket at the bottom of that, systems with high memory pressure can actually lock up. So…I’m gonna go with no.
As for Ubuntu, with the install process it doesn’t give me any chance to do anything other than choose the ZFS root method, and once I confirm it all, it just does it all in one shot, no chance for me to do anything in the middle before it starts actually copying stuff.
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